Onion peel and coarsely chop. Bread soaked in water and squeeze. Bread, onion and parsley to put in a machine and very fast to process in “pulse” mode in a homogeneous mass. Add the meat and run the combine, but only to ensure that the meat was finely ground, but not turned to mush! These operations can be done with the grinder. The stuffing to put in a bowl, add salt and pepper to taste, add the dry mustard and egg yolks. Mix into a homogeneous mass. If you pour cold water. Separately beat the whites in a steady but not too steep foam. The foam using a wooden spoon, gently combine with meat.With wet hands to mould round or oval cakes and fry in oil on both sides.